Recirculate BOV for SR? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

2plus4plus0eq6 · 11-12-2016, 08:18 PM

Hey guys,

I currently have a HKS SSQV BOV on the cold pipe of my s14 sr20det. Its just vented to atmosphere. I have been having some idling, and stalling issues. Also my A/F meter reads lean sometimes when I really don't think it is lean. I read somewhere that if my BOV isn't recirculated back into my intake, then I could have some issues because the ecu is dumping more fuel than it needs for the air since I am losing air from the BOV venting.

In order to recirculate it properly, would I have to move the BOV to the hot pipe and then vent it into the intake? or can I leave it on the cold pipe and vent it between my turbo and MAF?

I have also heard of blow-thru a little but seems like a rework in piping. its like sticking the MAF just before the intake and then throwing the BOV on the cold pipe to atmosphere? That way the engine runs properly and retains the loud BOV sound?

Any thoughts? thanks

derass · 11-12-2016, 10:25 PM

Generally, cars with MAF require a recirculated BOV. Otherwise, there are stalling issues as you mentioned.

You don't have to relocated your current BOV, just get the adapter and run the hose to the intake. It's done similarly from factory.

I wouldn't do a blow-though setup with the stock MAF. That's not what it was designed for, it risks damaging it.

*anti tyler* · 11-12-2016, 11:00 PM

Quote:

Originally Posted by derass

Generally, cars with MAF require a recirculated BOV. Otherwise, there are stalling issues as you mentioned.

You don't have to relocated your current BOV, just get the adapter and run the hose to the intake. It's done similarly from factory.

I wouldn't do a blow-though setup with the stock MAF. That's not what it was designed for, it risks damaging it.

So you have some options, do this or run blow through.

I've had a blow through setup for 8 years, that's not to say your mass airflow sensor will last that long.

Otherwise recirc it back to after mass airflow sensor. That air dumping had already been accounted for by the MAFs, if it doesn't get put back into the system after the sensor it will choke.

Kingtal0n · 11-13-2016, 11:53 AM

The HKS SSQV is one of the few you can run without a recirculation. It closes too early, leading to surge behavior, but as long as it doesn't leak it should be fine without going back to the inlet.

I would perform a pressure test ("boost leak test") and inspect the inlet side (between air filter and compressor inlet) for leaks, that is one place a lean behavior can result from any leaks there.

Second, the maf may need to be cleaned. If the car was running fine then all of the sudden got worse, try that, or try changing it, or moving it. The wires or something may have gotten fuzzed up. Remember that a leak on the pressure side (post compressor) means the a/f will get RICHER not leaner, thus a leaky BOV will leave you rich with fuel.

Otherwise, look at fuel pressure, do a compression test for peace of mind, and inspect the fuel system the best you can, change the fuel filter and look for anything obviously wrong with it like bits of rust in the lines from an aging fuel tank.

2plus4plus0eq6 · 11-13-2016, 01:31 PM

Thanks for the replies guys.. I just got the car on the road in the last year or so and haven't really had the time to drive it. Just trying to resolve a bunch of bugs I have noticed after the swap. I wouldn't say the car has ever run 100% so I have nothing to compare. I think the BOV (non-recirculating) is causing some issues. We will find out once I recirculate it. I really don't want to lose the loud BOV sound that I have, but performance is more important to me.

Anyone have any ideas of an adapter I could grab so I can vent it back into the pipe or coupling between the turbo and the Maf? I guess it would have to be of a similar size of the BOV vent adapter that goes onto the HKS

Thanks

derass · 11-13-2016, 03:12 PM

I was talking about this:

HKS includes it in some of their vehicle-specific BOV kits. Doesn't look like it's available seperately anymore. I thought at one point it was.

However, there are aftermarket version available. Here's one with a 1" hose diameter, they have 1.25" as well. Just match the size to the hole on the inlet pipe.

http://www.frsport.com/ATP-ATP-FLA-1...et_p_9910.html

edit: I stand corrected, looks like the adapter are available from HKS, here are the p/n's:

2plus4plus0eq6 · 11-13-2016, 04:06 PM

Quote:

Originally Posted by derass

I was talking about this:

HKS includes it in some of their vehicle-specific BOV kits. Doesn't look like it's available seperately anymore. I thought at one point it was.

However, there are aftermarket version available. Here's one with a 1" hose diameter, they have 1.25" as well. Just match the size to the hole on the inlet pipe.

http://www.frsport.com/ATP-ATP-FLA-1...et_p_9910.html

edit: I stand corrected, looks like the adapter are available from HKS, here are the p/n's:

I believe I have the adapter somewhere. It came with my BOV. I just need an adapter for the other end now

derass · 11-13-2016, 04:38 PM

Gotcha, I misread your previous post. You'll just need a straight piece of pipe that will fit between the circulation hose and the intake pipe.

11-12-2016, 08:18 PM	#1
2plus4plus0eq6 Zilvia Junkie Join Date: Oct 2005 Location: Canada, BC Posts: 390 Trader Rating: (0) Feedback Score: 0 reviews	Recirculate BOV for SR? Hey guys, I currently have a HKS SSQV BOV on the cold pipe of my s14 sr20det. Its just vented to atmosphere. I have been having some idling, and stalling issues. Also my A/F meter reads lean sometimes when I really don't think it is lean. I read somewhere that if my BOV isn't recirculated back into my intake, then I could have some issues because the ecu is dumping more fuel than it needs for the air since I am losing air from the BOV venting. In order to recirculate it properly, would I have to move the BOV to the hot pipe and then vent it into the intake? or can I leave it on the cold pipe and vent it between my turbo and MAF? I have also heard of blow-thru a little but seems like a rework in piping. its like sticking the MAF just before the intake and then throwing the BOV on the cold pipe to atmosphere? That way the engine runs properly and retains the loud BOV sound? Any thoughts? thanks __________________

11-13-2016, 01:31 PM	#5
2plus4plus0eq6 Zilvia Junkie Join Date: Oct 2005 Location: Canada, BC Posts: 390 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for the replies guys.. I just got the car on the road in the last year or so and haven't really had the time to drive it. Just trying to resolve a bunch of bugs I have noticed after the swap. I wouldn't say the car has ever run 100% so I have nothing to compare. I think the BOV (non-recirculating) is causing some issues. We will find out once I recirculate it. I really don't want to lose the loud BOV sound that I have, but performance is more important to me. Anyone have any ideas of an adapter I could grab so I can vent it back into the pipe or coupling between the turbo and the Maf? I guess it would have to be of a similar size of the BOV vent adapter that goes onto the HKS Thanks __________________

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11-12-2016, 10:25 PM	#2
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 33 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	Generally, cars with MAF require a recirculated BOV. Otherwise, there are stalling issues as you mentioned. You don't have to relocated your current BOV, just get the adapter and run the hose to the intake. It's done similarly from factory. I wouldn't do a blow-though setup with the stock MAF. That's not what it was designed for, it risks damaging it.

11-13-2016, 11:53 AM	#4
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	The HKS SSQV is one of the few you can run without a recirculation. It closes too early, leading to surge behavior, but as long as it doesn't leak it should be fine without going back to the inlet. I would perform a pressure test ("boost leak test") and inspect the inlet side (between air filter and compressor inlet) for leaks, that is one place a lean behavior can result from any leaks there. Second, the maf may need to be cleaned. If the car was running fine then all of the sudden got worse, try that, or try changing it, or moving it. The wires or something may have gotten fuzzed up. Remember that a leak on the pressure side (post compressor) means the a/f will get RICHER not leaner, thus a leaky BOV will leave you rich with fuel. Otherwise, look at fuel pressure, do a compression test for peace of mind, and inspect the fuel system the best you can, change the fuel filter and look for anything obviously wrong with it like bits of rust in the lines from an aging fuel tank.

11-13-2016, 03:12 PM	#6
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 33 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	I was talking about this: HKS includes it in some of their vehicle-specific BOV kits. Doesn't look like it's available seperately anymore. I thought at one point it was. However, there are aftermarket version available. Here's one with a 1" hose diameter, they have 1.25" as well. Just match the size to the hole on the inlet pipe. http://www.frsport.com/ATP-ATP-FLA-1...et_p_9910.html edit: I stand corrected, looks like the adapter are available from HKS, here are the p/n's:

11-13-2016, 04:38 PM	#8
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 33 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	Gotcha, I misread your previous post. You'll just need a straight piece of pipe that will fit between the circulation hose and the intake pipe.